Not sure if this is good or bad yet
I absolutely love Jungledisk - apart from the fact that the software is really good, it has "free upgrades for life" once you drop your initial 20 USD, the software works on Windows, Mac OSX and Linux, the developers are very responsive to user comments/problems etc, AND they have fantastically unusual licensing terms - ie. you can install the desktop edition on as many computers as you want. And Amazon S3 seems a very good backend for storage, it's cheap, and yet I don't expect Amazon to go kaputt taking my family photos with it any time soon. Also, JD provide an open source bit of code that could always restore your data from S3, even if the (JD) company suddenly disappeared from the face of the Earth without warning. I know S3 famously doesn't have 6 nines reliability, but it's good enough for my home PC backups.
SO, now Jungledisk has gone from two men and a dog, to being taken over by a big corp, I can see this too-good-to-be-true product getting gradually eroded in goodness, maybe. On the plus side, the planned version that hosts with Rackspace might compete with S3 on price, and being taken over maybe secures their (JD's) future. Comments on the user forums seem to reflect this split view so far - some people are pleased, others are worried. Personally, I hope the S3 version isn't left to wither on the vine. I like being charged a couple of quid a month for my backups on a pay-per-use basis, with a product where I have a user-supplied encryption key and no-one but me can see what I'm backing up (well OK, me and the three letter agencies, but they are not too likely to be interested). Also I like that the backups are not hosted or controlled by the people who supplied the software (ie. JD). Generally speaking, the software does not necessarily ever have to interact with any JD servers, only with Amazon S3 (although if you opt for the better JD+ service, that is not true then - it backs up via JD controlled EC2 servers).
If only Jungledisk had syncing abilities like the similarly cross-platform dropbox, it'd be perfect.
Anyway - only time will tell - I've got my fingers crossed.
Biting the hand that feeds IT
